Change HDMI resolution on Nitrogen6x board with Ubuntu

I started working with an Фреескале i. MX6Q rev1.2 at 792 МГц в few days ago. I got the Nitrogen6X board with 2GiB DRAM and I am using an Ubuntu image from https://boundarydevices.com/.

So I connected в монитор to the HDMI port. The монитор is capable of many resolutions (I want to использовал the max resolution 1920x1080). The image however ты существуешь not this resolution.

I connected the board серийный путь интерфейс to my laptop und checked the output during the boot process. Here, U-Boot tells я, HDMI is used and resolution is set to 1024x768.

No panel detected: default to HDMI
Display: HDMI (1024x768)

гve used google and found some solutions, but they didn't work for я:

1.) I tried setting bootargs in U-Boot with

setenv bootargs video=mxcfb0:dev=hdmi,1920x1080M@60,if=RGB24
saveenv
boot

but it had не effect at all.

2.) I checked the output of cat /sys/class/graphics/fb0/modes which gave я the following:

U:1280x720p-60
U:640x480p-59
U:1280x720p-120
U:1280x720p-100
U:1920x1080p-30
U:1920x1080p-25
U:1920x1080p-24
U:1920x1080p-50
U:1440x576p-50
U:1440x576p-50
U:1440x288p-50
U:1440x288p-50
U:1280x720p-50
U:720x576p-50
U:720x576p-50
U:1920x1080p-60
U:1440x480p-60
U:1440x480p-60
U:1440x240p-60
U:1440x240p-60
U:1280x720p-60
U:720x480p-60
U:720x480p-60
U:640x480p-60

but I don't know how this helps я.

3.) I tried changing the resolution by navigating to Menu->Preferences->Monitor Settings but this tells я that не monitors пахал detected and therefore I хан not change the resolution.

So I am still stuck to в resolution of 1024x768. How хан I change it?

Thanks for your help in advance.

Dambe